1. Field of the Invention
The present invention relates to methods and systems for transceiving information between mobile stations and base stations, and in particular to a method and system for determining if a received message was transmitted via a repeater.
2. Description of the Related Art
Cellular telephone (cellphone) service has become widespread. In some service areas, it has become mandatory that cellphone service providers incorporate features into the cellphone network that allow the location of the cellphone user to be determined. These services are useful for, among other things, emergency calls (911 and the like).
In providing this service, difficulties arise when the cellphone user is communicating with the base station of the cell via a repeater. In such circumstances, the position determination system cannot distinguish where the cellphone user is, since such systems typically do not identify the signal to the user as having been received from the repeater, and the usual means of determining the user's location (e.g. triangulation using signal strength and other signal measures) can be compromised by passing through the repeater. For example, a repeater typically adds 4–10 μsec to the signal propagation time, which can cause position ambiguities. Further, forward link signals received from a repeater are indistinguishable from those forward link signals received directly from a base station.
It is also desirable in some circumstances to monitor network traffic, particularly traffic passing through the repeaters. This allows monitoring of call statistics in a repeater area. This capability is also difficult to implement unless the base stations are capable of identifying which received transmissions were received via the repeater and which were not (e.g. received directly from the cellphone).
What is needed is a simple system and method for identifying whether a particular cellphone transmission was received directly from the mobile station, or whether the transmission was received via a repeater. What is also needed is a simple system that is operational with cellular telephone systems that include power control capabilities. The present invention satisfies these needs.
What is also needed is a simple system and method for identifying whether a particular base station transmission was received directly from the base station, or whether the transmission was received via a repeater. What is also needed is a simple system that is operational with cellular telephone systems that include power control capabilities. The present invention also satisfies these needs.